2008 6T70 Transmission whining.
 

It had been working perfectly and quietly since I got it a few weks ago. Now it's whining noticeably. I'm a bit concerned that the 3-5 wave plate could be damaged and about to come apart. What are the symptoms? I already bought a Sonnex wave plate upgrade kit if I need to pull the clutch pack out.

Symptoms are intermittent or complete lack of reverse, shift flares from three to four and five to six.

Easiest way to sort out the shift flares and confirm which gears are involved is to put it in tap shift mode. Drive normally while tap shifting manually. When you up shift, the flare will be obvious as the RPMs will increase before slapping into the next higher gear.

Think I had before choosing her parking spots as losing reverse complicates matters.

I will also pass on that summer along the line I read that you must thoroughly thoroughly flush the torque converter to ensure any fragments are removed from the system.

If you find fragments in the torque converter I believe replacement is suggested.

I think it is the TSB on this. I will come back w a link.

#09-07-30-012F is the original Saturn TSB.

the attached Service Bulletin 14404 B (2016) is from GM, describing their extended warranty relating to this defect, and includes instructions on how to evaluate what needs to be replaced based on what you find once you get in there.

I consider them to be time bombs. If it does break, it stands to do potentially much more damage than if it remains intact. Consequently, if you have the kit and the skills with the tools, I would replace it before it becomes an issue.

See attached.

Will a flush clear the filter?

No, a flush won't clear the filter, unfortunately. You need to get a new filter. IMHO, flushing is a waste of time and money. The old filter will still have crud in it that won't come out. You're a smart dude, so treat that car like you would if it was the MG having issues like this.

Can't remember if it has an internal filter but if it does, I doubt it will clear it. Usually you have to crack the case for that